Vesicoureteral reflux (VUR) is the backward flow of urine from the bladder into the kidney.

Urine normally flows from the kidneys, through tubes called ureters, then into the bladder. Each ureter connects to the bladder in a way that prevents urine from flowing back up the ureter (similar to a one-way valve). When this mechanism does not work properly, or the ureters do not extend far enough into the bladder, urine may flow back up to the kidney. If the urine contains bacteria, the kidney may become infected. The backup can also put extra pressure on the kidney, which may damage it.

This is a potentially serious condition that requires care from your doctor. The sooner VUR is treated, the more favorable the outcome. If you suspect you or your child has this condition, contact your doctor immediately.

Anatomy of the Renal System  

© 2008 Nucleus Medical Art, Inc.

This condition may be caused by:

• A problem in the way the ureter inserts into the bladder
• A ureter that does not extend far enough into the bladder
• Bladder outlet obstruction (eg, blockage of urine flow from an enlarged prostate gland)
• Neurogenic bladder (loss of normal bladder function due to damaged nerves reaching the bladder)
• Temporary swelling after kidney transplant

The following factors increase your chance of developing VUR. If you have any of these risk factors, tell your doctor:

• Family history
• Congenital abnormalities of the urinary tract
• Birth defects that affect the spinal cord, such as spina bifida
• Tumors in the spinal cord or pelvis
• Spinal cord injury

In most cases, VUR produces no obvious symptoms or signs. It is often discovered after a kidney infection is diagnosed. Infants with swelling of the kidneys ( hydronephrosis ) on prenatal ultrasound may have this condition.

In some cases, VUR produces no obvious symptoms or signs.

Your doctor will ask about your symptoms and medical history, and perform a physical exam. In rare cases, high blood pressure may be an indication of kidney damage due to long standing VUR. Tests may include the following:

• Blood tests—to assess how well the kidneys are functioning
• Urine tests—to look for evidence of an infection or damage to the kidneys
• Ultrasound—a test that uses sound waves to examine the kidney and bladder
• CT scan —a type of x-ray that uses computers to make pictures of structures inside the body
• Voiding cystourethrogram (VCUG)—a liquid that can be seen on x-rays is placed in the bladder through a catheter; x-rays are taken when the bladder is filled and when urinating.
• Intravenous pyelogram—a liquid that can be seen on x-rays is injected into a vein; x-ray images are taken as the substance travels from the blood into the kidneys and bladder,
• Nuclear scans—a variety of tests using radioactive materials injected into a vein or the bladder to show how well the urinary system is working

The goal for treatment of VUR is to prevent any permanent kidney damage from occurring. Treatment options include the following:

• Observation—Most cases of VUR in children clear up on their own, as the ureters continue to develop. The treatment may involve regular urine cultures, antibiotics, and annual check-ups on kidney functions to follow development. Children are advised to stay well hydrated and to frequently empty their bladders.
• Prophylactic antibiotics—Children at risk of infections or who have had many infections are often placed on low dose, daily antibiotics.
• Endoscopic injection into the ureter—Minimally invasive surgery can be used to correct reflux. A chemical (eg, Deflux) is injected where the ureter inserts into the bladder to create a mechanism to prevent urine from going backwards up the ureter. This procedure is done through a small tube called a cystoscope, which doesn't involve any incisions.
• Ureteral reimplantation—Surgery is performed to diminish reflux by repositioning the ureters in the bladder.

To help reduce your chances of developing complications from VUR, seek prompt treatment for bladder or kidney infections. This is particularly true if you have a neurogenic bladder.